metcalfe



' 1,630,201 1927 v. E. METCALFE CEN-TRIFUGAL SEPARATDR Original Filed A112. 16. 1923 my v 4 Sheets-Sheet 1 1,630,201 May 1927' v. E. METCALFE CENTRIFUGAL SEPARATOR Original Filed Aug. 16. 1923 4 Sheets-Sheet 2 4 1927. May 2 v. E. METCALFE CENTRIFUGAL SEPARATOR Jrvuenfot Qttozwug 4 Sheets-Sheet 3 Original Filed Aug. 16. 1923 V. E. METCALFE CENTRIFUGAL SEPARATOR Original Filed Aug. 16 1923 4 Sheets-Sheet 4 0 H g H it D Q Patented May 24, 1927.

UNITED STATES VIRGIL E. METCALFE, OF

DELICLAS, oRrm TE, CUBA.

CENTRIFUGAL SEPARATOR.

Application filed August 16,1923, Serial m; 57,739- Renewed April 6, 1927.

This invention relates to centrifugal separators and more particularly to centrifugal separators having an outer rotating perforated basket and an inner rotating conveyor.

The main object of the invention is to provide a centrifugal separator having the above mentioned main elements and means for conveniently controlling the speeds of these elements.

' A further object of the invention is to so arrange the rotating basket and conveyor as to materially reduce the power necessary to rotate the elements relatively to eachother. With these and other objects in view, as will hereinafter appear, theinvention consists in the novel construction and arrangement of parts including a novel transmission mechanism constituting the apparatus, all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

For a\ complete understanding'of the invention. reference is to be had to thefollowingv description and the accompanying drawings in which ig'. l is a vertical sectional view of the apparatus;

Fig. 2'is a top plan View;

' line 3+3 Fig. 3 is a cross section on the of Fig. 1 z Fig. 4 is a cross sectioni'of Fig. '1 on the line 44; v Fig.5 is a diagram of-the electrical transmission; and f Fig. 6 is a. fragmentary side'elevation of two. perforated baskets joined together.

Referring to the drawings in detail, the

reference character 1 designates aperforatcd basket to which is joined another basket 1,

I each basket being of the shape, by preference, of a truncated cone. basket, concentric therewith and ade uately spaced therefrom, is a conveyor. which is preferably of theArchimedes screw type, said conveyols being represented by the numerals 2 and 2. It will be understood that' in theprocess of separating liquid material from the solid particles, centrifugal force exerted by the basket which is caused to rotate as will presently appear will expelv the liquid through the perforations of the basket while the solid particles will be retained therein between it and the outer surface of the conveyor which by rotating at'the proper speed with respect to the basket will cause the solid particles to be forced longitudinal- Interior -of each ly. of the basket to the open end thereof where the solid articles will be caught in a suitable receptacl In order to obtain accurate rotative speed relation between the basket and the conveyor, there is provided a novel electric transmission which will be presently described. There is arranged a'fixed shaft 3 secured toia'. suitable pedestal or standard 4, and secured to. this shaft 3, isthestator A of a phase wound inductionfmotor." Journalled on the shaft 3 and having-rollerbearing connection therewith, as clearly shown by Fig.

;1 of the' jdrawings, is a rotor B having a phase winding mounted in its inner-surface, and this winding is 5 connected to" a" similar winding positioned slots'in' the outersurface of the rotof'B, the latter winding being designated by the reference 'characte'r' B.

tRotatively mountd'flon the rotor B is art tor on" theinne'r surface of which is'pla'ced lafshort circuitedwinding; ltwill be re'adily ,rappa'rent that the stator A androtor 'B-"conf titute a phase 'wouiid induction motor; while I the rotor considering the winding B only,

" and 'the'fi-oto'r C constitutea squirrelcage induction. motor. Thugi'there are provided two ,in'duction" motlor's wherein 'the"'-'i'nner "re irs o h. 1. b h ec l y member withrespect to'theipriniary member "A, ,and'the winding B is a primary member withmespectto the rotor C which is 'a' sec- 1 ondary member.- 'Tbe "terminals of the stator winding A'may pass; through the axial bore'3" in the,endof the sha'ft 3g- Reference here-made to, .igJ-5 of thedr'awings for a clear understanding'of the "electrical transmission. To control the voltage impressed ion the] stator A'for' a purpose to be presently explained more ind'etail there is provided a three phase induction voltage regulator R.

When-the'windiiig'onthe stator A. is excited from a} suitable power circuit, acurrent is generatedin the inner winding of the ele- "-ment B, causing ittorevolve, and this current also excites the outer winding B which in turn inducesthe fiowof'current in the element C. The speed of element Bwill in crease; to some value below synchronism de- 1 pending upon the slip, and ifthe element C is connected to run in the same direction as B, its speed willbe greatertlian that of B depending upon theslip'between A and B,

constant 'loadand voltage.- If for assuming any reason, there is a change in slip of B .made in two. parts. so,

with respect to A, there will be a change in the relative speeds of B and C, and comparatively small changes in slip between A and B will cause comparatively large changes in the relative speeds of B and C. Now. the slip in an induction motor under constant load becomes greater with a de-' crease in the. impressed voltage and. less with an increase of voltage. Taking advantage 0t this principle, it is proposed to. control the relative speeds of B. and C by varying the voltage on the stator A. by 1193115 oi the induction voltage regulator R. lit is thus apparent that a very con enient means of controlling the relative speeds of the basket and the conveyor may be employed by connecting the basket to one and the conveyor to the other of the elements B and C.

Accordingly, the conveyor 2; is connected to the element C at the projection 5 of. the hub (i by which the rotor C is mounted on the hub. 7, oi the rotor B, as is obvious. from an inspection, of Figaliand the basket 1 is connected so as toberotated. bythelrotoi: B

- bv means of-the spider arms 8 which are secured to, the. hub. 9 by means. of bolts. 10. It will be UJAClQIStOQClJ that the basket 1 rotates with the basket 1 by reason oi the factthat they are joined at their adjacent endsor are integral with each other,.as maybe desired.

is likewise. rotated-. by the be seen more clearly being joined A ball The conveyor 2 conveyor 2*, as may from Fig, 1, the two; conveyors together at their contiguous ends.

- bearing 11 is. provided between the baskets 1, 1 and the conveyors2, 2. At the to y of conveyor 23, is a, di 1: 12, spaced from a. sk 13 at the bottom ofthe, conveyor 2fby the studs 12?, theupper disk 13. having an open- 14 provided with upstanding defleeting rim 14: whereby-: the .materiat received from. the spout 15 is divided, part passing to the upper basket, 1 and. the rest passing to the lower; basket 1;: The conveyors 2 and Zf areprovided with, openings through which the material may fimv to. the baskets.

The liquid, materialthat is expelled through the baskets on-screens]. and 1 will be caught in therece-iver 16, havingtheopening- 17 through, which. the liquid; may be remoyed, the, solid particles will be expelled at the ends at the baskets nd will be caught in the recetacles 1,8 and 19 at the upper andlower en- .ot the apparatus. The

receptacles 18. and L9; may. preferably be that each receptacle may be remtwcd, at will. In Fig. 4,, the. receiver 19 is shown in. two parts, and it will he understood that the neceiver 18.n1ay be likewise constructed and arranged. Any

suitable supports for the receivers 18 and.

19 may he provideghbut the upperqrecepta- (-lc is. supported for example, on. the arms 21) spaced vim-umlurentially of the receiver 16, and the lower receptacle is supported on the arms 21. radiating from the! base or standard 4.

When it is desired to wash the solid particles before being discharged, water connections 22 and 22 may be employed, baffles 23' and 23 being arranged to prevent the water from coming in contact with the material near the top and bottom of the upper and lower baskets respectively. It will be obvious that steam connection may be made with the cylinder receiver 16 so that steam may be admitted between the whirling basket and the receiver for periodically cleaning thebasket when necessary or desirable.

The apparatus. has. bcQ i described in detail and its operation is believed to be clearly understood.. (bite the centrifugal separator is. capable of use generally, it is'especially advantageous for drying sugar and S parating the. molasses from the sugar. A. continuous stream ofmassecui e m y be. admitted thronghtlw spout 15; Thest'ream will, di-

vide, and pass to the upper: andlo'wci; baskets saryt espeintedz ou above, :any.. small change in the shp between the stator A, and

the rotor B. will; be reflected in a' coin ratively large change in'the relative specs of the rotor-B and the. rotor Qanid consequently betwe n he spe ds. ith i baske s and t conveyors." Thereforeyfor fine adjustments 2t small'change in the im ressedivoltage will give-the desired change in the speed of the conveyor: with respect. to the basket. Forexamplle, with the machine in operation, the sugar discharged. con a ustoo muc molasses. and, itis desiredftol obtain a dryer sugar, the relative speeds-of the basket; and the coneyor-may be adjusted. by vary ng. h voltage on thetstator to cause the sugar toremain in, th basket for a longer period to enable a 155.8 PQ iQ 0i. action. Qf'th centrifugal force of the rotating basket to expel; the molasses. It is thus apparent th t a very fine ustment may be made, thus making; it possible to produce different grades of sugar of uniform quality.

From theal' ove description, it will be aparent thatit is not essentialto my invention provided, but in order to ofiset the end that of the basket,

thrust of the rotating screw, the two baskets and conveyors are arranged as shown so that the end thrust of one conveyor neutralizes the end thrust of the other conveyor.

It has already been noted that by mounting the motor for actuating the conveyor up on the motor that actuates the basket, only sufficient power to operate the conveyor at the difference in speeds is necessary as distinguished from the power necessary to operate the conveyor if its operating motor were not mounted on the basket operating motor. It is also important to note that if the conveyor is made to operate in a direction opposite to the falling massecuite in frictional contact with the disks l2 and 13 will exert a retarding action on the conveyor in such a direction as to aid the conveyor operating motor.

The foregoing disclosure contains a more or less general description and illustration of the preferred embodiment of the invention, but the mechanical details and expediencies may be supplied to suit different conditions that may arise. In view of the disclosure, certain changes in the construction and arrangement of parts may be made, but since the description and drawings are to be considered illustrative only of the invention, it is to be understood that this invention contemplates all such changes as come within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States is:

1. In acentrifugal separator, a rotatable annular screen, an inner rotatable conveyor coaxial with said screen, and means for varying the speed ratio of said rotatable screen and conveyor comprising electroinductive means for operating said screen and conveyor.

2. In a centrifugal separator, a rotatable annular screen, an inner rotatable conveyor, an induction motor for operating one of said elements, and an induction motor for operating the other of said elements, the rotor of one of said induction motors comprising the stator of the other of said induction motors.

3. In a centrifugal separator, a rotatable annular screen, an inner rotatable conveyor, an induction motor for operating one of said elements comprising an internal stator and an external rotor, and an induction motor for operating the other of said elements com prising the rotor of saidfirst mentioned induction motor and a rotor in electro-inductive relation therewith.

4. The combination of a centrifugal separator having an outer rotating element and an inner rotating element, means for rotating said elements with respect to each othei comprising an induction motor for each ele ment, one element of one motor being in inductive relation with an element of the other motor whereby variations in slip of one motor cause variations in the speed ratio of the two motors, and means for varying the slip of one of the motors.

5. In a centrifugal separator, an outer rotating element and an inner rotating element, a fixed shaft, an induction motor stator secured to said shaft, a rotor for said induction motor surrounding said stator for operating one of said elements, and a rotor in inductive relation with said first mentioned rotor for operating the other of said elements at a speed proportional to the speed of the first mentioned element.

6. In a centrifugal separator, a rotatable annular screen, a rotatable conveyor, a fixed shaft coaxial with said conveyor and screen and arranged within said conveyor, an induction motor stator secured to said shaft, a rotor rotatably mounted on said shaft for rotating one of said rotatable elements, and another rotor inductively related to said first rotor and rotatably mounted thereon for operating the other of said rotatable elements.

7. The combination of two rotatable members and means for rotating said members at different speeds comprising two induction motors, the primary winding of one motor being connected to the secondary winding of the other motor, and means for varying the impressed voltage on one of said motors. to thereby vary the slip of said motor and thereby vary the speed ratio of the two motors.

8. The combination of a centrifugal separator having two rotatable members and means for rotating said members at different speeds comprising two induction motors, the primary of one motor being connected to the secondary of the other motor, whereby variations in slip of one motor causes variations in the speed ratio of the two motors, and means for varying the slip of one of said motors.

In witness whereof, I hereunto aflix my signature.

VIRGIL E. METCALFE. 

